Quite personally? Albedo from the Novels is slighty different by the artstyle (More round eyes, anime syndrome). But it is not like she is that different, MADHOUSE can not simply match this kind of character design into their animation 100% accurately.

Spoiler

As for her personality, she is really great as a guardian and overall hilarious when it comes to the Romance gags, mostly because her creator Tabula Smaragdina was a fan of moe, heavily influencing Albedo's personality, just like his love for horror movies influenced Albedo's sister, Nigredo.

It just feels that her voice doesn't suit Albedo's mischievous character. She's a succubus for crying out loud, she oozes sex from every pore. Hara Yumi's voice just doesn't have that depth, maturity and lustful desire in it. Doesn't sit well with me, but oh well.